EP0123183B1 - Processing machine for flat workpieces - Google Patents

Description

The invention relates to a processing machine for flat workpieces with a processing station and a first workpiece holding device (34) which can be moved and actuated in a straight line (for example in the X direction) with respect to its processing tool by means of a first feed device (11, 12, 13). and with an additional workpiece holding device (35) which can be moved and actuated in the same direction at least as an alternative to the first by means of an additional feed device (7, 4, 8). Such a machining machine is known for example from DE-A-28 48 282. More precisely, it is a punching machine that is used to perforate metal sheets, which are subsequently processed into washing machine drums. A sheet corresponding to the unwound drum shell is brought into the area of the punching tool with the aid of the first feed device and its assigned first workpiece holding device. It is then taken over by the additional holding device, whereupon the first holding device is released. During punching, the workpiece is only held by the additional holding device. This has two clamping claws which are arranged at a distance from one another and are connected to one another via a cross strut. One is the front and the other the rear workpiece or. Assigned sheet end. After punching all the holes, the workpiece is transported out of the machine with the aid of the first holding device and its feed device. After all devices have been returned, a new cycle begins.

In this processing machine, the workpiece is always held by only one of the two holding devices during transport and during processing. The two holding devices are only briefly closed when the machine is at a standstill. The sometimes quite high forces that occur during machining are therefore absorbed by only one holding device, namely the additional holding device. When punching and nibbling, the workpiece must be accelerated strongly between two punching strokes and braked again. This results in high loads on the holding device.

In the previously known machine, it is now considered disadvantageous that the first holding device is inactive during punching and thus does not contribute to absorbing the high loads. On the other hand, this requires a particularly high holding force of the additional holding device. This could be kept much lower if both holding devices would hold the workpiece during punching.

The claws of the additional holding device hold the workpiece at the front and rear end in the direction of displacement. Because none of these claws can be loosened during machining, machining in the area of these claws is not possible. If you opened the claw at one end, rotating the workpiece around the claw at the other end would be almost inevitable. Overall, one is considerably restricted with regard to the formation of the workpieces.

Apart from this, one is of course very limited with regard to the machining of workpieces simply because the workpiece can only be moved in one direction.

As already mentioned, the previously known processing machine is a punching machine. Flat workpieces, in particular sheet metal, are not only punched or nibbled, but rather are thermally processed on similar processing machines, for example in the plasma or laser cutting process, milled or processed with other known tools, the term "tool" here being understood in the broadest sense is and for example also includes a burning nozzle or the like.

In all of the methods mentioned, displacement of the workpiece in only one direction is generally not sufficient. In order to machine or create oblique, curved or circular contours, a workpiece feed in two mutually perpendicular directions is necessary, the displacement movements being able to be superimposed on one another in a known manner. In addition, a processing machine is of lesser importance if it does not allow the processing of certain zones of the workpiece due to the workpiece holding devices. Finally, it is essential, particularly when machining heavy and large workpieces, that the machine has the necessary stability and vibration rigidity.

The object of the invention is consequently to further develop the processing machine of the type described in the introduction in such a way that the load on the workpiece holding devices which occurs when the workpiece is accelerated and decelerated is reduced, processing in all edge regions is made possible and more universal workpiece processing is possible.

To achieve this object, it is proposed according to the invention that the processing machine is designed in accordance with the preamble of claim 1 in accordance with the characterizing part of this claim. Since the two opposite workpiece edges assignable workpiece holding and feed devices can be moved both individually and jointly within a common XY plane and can also be actuated separately or jointly, ie open and closed, on each side, one can on this Machining the workpiece to be machined either only with one or the other workpiece holding and feeding device relative to the machining tool or alternatively using both workpiece holding and feeding devices. The latter is particularly indicated for large and heavy workpieces. Because of the common control devices, a change from one to the other workpiece holding and feeding device or from one to two or vice versa is not difficult. As a result, a workpiece can easily be machined to all edges. If the machining is to take place in the area of the workpiece holding and feeding device, this is at least temporarily removed or not used at all. As soon as this point has been machined and there is nothing to prevent the workpiece holding and advancing device from being attached at this point, the workpiece can be held there again or for the time being. As a result, machining on the opposite side in the area of the other workpiece holding and feeding device is possible without further ado.

If the workpiece is held on opposite edge areas at the same time, each device only has to apply half the maximum clamping force required, which is why it can be dimensioned comparatively small in this direction or the required clamping power can be designed accordingly lower. It is also possible to change the lateral distance between the two workpiece holding and feeding devices, so that workpieces of different sizes can be held

Finally, the movement of the workpiece in the X and / or Y direction enables diverse machining. When holding the workpiece simultaneously with both workpiece holding and feeding devices, the focus of the workpiece consisting of a sheet metal plate lies between these two devices. An overshoot when accelerating and braking the workpiece, for example between two punching or nibbling strokes, is thereby eliminated or is at least considerably damped. The risk of tearing out of one of the two devices is also considerably reduced.

As stated, the two workpiece holding and feeding devices can be moved in the same direction. It must then be ensured, particularly with an automatically controlled feed movement, within an X-Y plane that both devices receive appropriate commands so that on the one hand they are moved synchronously and on the other hand neither prevents the movements of the other when both are attacking the same workpiece.

It is easy to see that such a processing machine can, for example, also machine two workpieces located next to one another on the same plane. With only a single processing station, processing is of course carried out in succession. On the other hand, alternating machining operations are possible on both workpieces, but not necessarily expedient.

Finally, there is also the possibility of dividing a workpiece into two parts using the or a processing tool as the only or last working operation and holding one of the two resulting parts with each of the two workpiece holding and advancing devices.

In a particularly preferred embodiment of such a processing machine, the common control is programmable. When machining small workpieces, for example, you can only use one of the two workpiece holding and feeding devices and this also applies if you cannot attach one of the two devices to a workpiece because the machining should be carried out wherever the second device would have to be applied. In this case it would be disadvantageous to let the unused holding device run "empty". Rather, it is expedient if the control is only allowed to act on the workpiece holding and feed device that is or is currently being used.

If both holding devices are moved, ie displaced, independently of one another by the control, the movements must take place in such a way that neither workpiece obstructs or even blocks the other. The preferred case is, however, in which the preferably programmable common control acts on both workpiece holding and feed devices in such a way that the latter hold a single workpiece together and move them for the purpose of machining.

If the workpiece holding and shifting devices engage or hold and shift the same workpiece, then with a program-controlled workpiece shift it must be taken into account that either the coordinate zero point of the two devices is separated by a fixed value, for example in the X direction or in the case of a common coordinate zero point of the two devices, the starting position of one device, for example in the coordinate zero point, lies while that of the other is shifted on the X or Y axis by a fixed value which must be taken into account during programming. Otherwise, the holding devices in the punching, nibbling or flame cutting machines known manner and be provided with drives.

A further embodiment of the invention is characterized in that the two workpiece holding devices lie opposite one another at a distance, holding members of the first workpiece holding device pointing in approximately opposite directions to holding members of the additional workpiece holding device. These holding devices are therefore particularly well suited for holding metal sheets or other workpieces with parallel workpiece edges. The holding members can, for example, have clamping jaws or the like or be designed as clamping claws, which can also be opened or closed via the machine control, and in the case of a program control also the opening and closing can be included in the program. This applies above all if you have to implement one or the other holding element during processing, because processing should take place at the point at which this holding element was previously applied. Here, too, the use of two holding devices with separately controllable holding members has a particularly favorable effect because each holding device or each of its holding members can be implemented independently of another if it is in the way for further processing. Basically, all of this happens when the workpiece is held steadily by the other holding element or elements, which is why there is no displacement of the workpiece relative to the machining tool or tools during this transfer. This avoids inaccuracies in the machining which can hardly be avoided with the implementation of the known processing machines with only a single holding device. Therefore, the side spacing of the holding members of each holding device can be adjusted separately in a further embodiment of the invention.

Another embodiment of the invention provides that the two holding devices are mechanically connected to one another and that they are located opposite one another in particular. In the case of a controlled movement of the holding device, a single control device that acts on one of the holding devices is sufficient, while the other is carried along via the mechanical connection. The mutual distance corresponds, for example, to the maximum workpiece width or length to be machined.

In a particularly advantageous manner, the processing machine has two processing stations for the workpiece that are spaced apart from one another. This can be the same as well as different processing stations. If the machining stations are different, then in the case of a program-controlled displacement of the workpiece when moving from one machining station to the next, its lateral spacing must be taken into account in the program. If, for example, a certain point is first nibbled and later reworked on a second processing station using a milling cutter, the workpiece must be moved by an amount which corresponds to the distance between the two tool axes and the edge to be removed during milling. When moving from one machining station to the next and simultaneously machining at another location on the workpiece, the displacement movement of the latter can be both larger and smaller than the lateral distance between the axes of the machining tools of the two machining stations.

In a preferred embodiment of the invention, the two processing stations are at a fixed distance apart in the same direction as the two holding devices. The width to be worked depends on the "throat depth", the distance from the processing station to the connection from the boom to the base. If the two processing stations have a fixed distance of approximately this throat depth, workpieces can be machined that are twice as wide as the throat depth.

Another preferred variant of the invention is characterized in that the two processing stations are located at least in part on mutually opposing machine arms. For example, in a punching or nibbling machine with an at least two-part machining tool, one part of the tool, in particular the punch, is located in a tool holder of the boom, while the other part or parts of this tool are inserted in a tool holder of a base frame. In the case of two mutually opposing machine arms, this processing machine can have, for example, two mutually opposing, possibly also interconnected arms, starting from a common base frame, in which case the two lower tool parts are then in the base frame and the associated upper tool part is used in each of the two or the common arm . However, it is not absolutely necessary for this machine to have a common base. It may be advantageous if the two sub-machines each have their own sub-frame with an associated boom, but in this case too, both sub-machines can be actuated by one and the same controller. However, this does not exclude that this control is a kind of overall control consisting of two partial controls and that if necessary, each of the partial controls can be used individually in connection with your partial machine.

According to another variant of the invention, it is provided that the second processing station is located at least in part on an extension of a machine extension arm. In this case, the processing machine expediently only has a common one-piece base frame and, in deviation from the conventional processing machines of this type, its machine arm is equipped with an extension arm extension on which the second tool or, in the case of a multi-part tool, the upper tool part, for example the stamp of the second machining tool.

The invention is explained in more detail below on the basis of exemplary embodiments. The drawing shows these exemplary embodiments.

• Fig. 1 Perspektivisch eine erste Variante in schematisierter Darstellung,
• Fig. 2 ebenfalls schematisch, eine Seitenansicht einer zweiten Ausführungsform.

Here represent:

• 1 perspective view of a first variant in a schematic representation,
• Fig. 2 also schematically, a side view of a second embodiment.

In both figures, details which are not essential for the explanation of the invention are omitted or only shown in a stylized manner. In addition, the details shown are partially enlarged for the sake of clarity and are also shown essentially simplified.

On the stand 1 of the processing machine, for example a punching or nibbling machine with two work stations, a rail 3 with a rack 4 is attached to the side. On this rail 3, a carrier guide 5 can be moved back and forth in the direction of the double arrow 6. This is achieved with the aid of an electric motor 7, the drive shaft of which carries a pinion 8. The teeth of the latter mesh with those of the toothed rack 4. A workpiece carrier 9 is mounted on the carrier guide 5 so as to be longitudinally displaceable in the direction of the double arrow 10 and can be driven by means of a second electric motor 11. The pinion 12 of this second electric motor 11 engages in the teeth of a second rack 13 connected to the workpiece carrier 9. The direction of movement of the workpiece carrier 9 is exactly perpendicular to that of the carrier guide 5.

In the embodiment of FIG. 1, two holding members 14 and 15 are mounted on the workpiece carrier 9 in a longitudinally displaceable manner in the sense of the double arrow 10 and can be fixed in any displacement position. Each holding member can have two clamping claws 16 and 17 or the like offset in the longitudinal direction of the workpiece carrier 9. The workpiece 18, for example a metal sheet, is therefore held with its longitudinal edge assigned to these holding members 14 and 15 at two laterally adjacent locations, so that one can hold the workpiece non-rotatably at this point when using or having only one such holding member. Furthermore, each holding member 14, 15 can have a latching receptacle 19, for example consisting of a bore, and a holding device 20, with the aid of which the holding member in question can be fixed in any displacement position on the workpiece carrier and released again if necessary.

The processing machine 1 is essentially symmetrical with respect to a plane indicated by the dash-dotted line 21. As a result, there is also a common subordinate 22, which is only indicated schematically. However, it can be divided in the region of the plane of symmetry 21 in a manner not shown, so that two sub-machines 23 and 24 are formed which, if this is considered expedient, can be connected to one another. This can be done with the help of suitable connecting flanges, tabs or the like. On the other hand, however, a reliable mutual association of the sub-machines 23 and 24 is possible in that each has at least four fastening feet 25 with which they can be anchored to the floor if necessary. In a known manner, each sub-machine has an approximately C-shaped frame, the upper C-leg forming a boom 26 or 27. There is an upper tool holder 28 and, in a manner not shown, an eccentric drive or the like, provided that it is a punching or nibbling machine. Of course, this is omitted in the case of a flame cutting machine or is replaced there by a burning device. In the upper tool holder, for example, a nibbling or punching punch can be used interchangeably. Accordingly, the lower tool holder 29 then receives an associated die and, if appropriate, also a wiper. It is entirely possible to provide different tool holders on the two sub-machines, so that, for example, one sub-machine serves as a punching or nibbling machine, while the other sub-machine is a plasma or laser internal combustion machine. All other combinations are also conceivable, for example the design of a sub-machine as a milling machine. In addition, the construction of this processing machine from two sub-processing machines does not preclude the fact that at least one of the latter has two tool holders arranged side by side or one behind the other, or more generally, processing stations. In the case of a program control, the lateral distance or the longitudinal distance of these two processing stations must then be taken into account accordingly when changing from one processing station to another in the program. A program control is indicated symbolically in the right submachine 24 and provided with the reference number 30. With their help, everyone will be expedient controllable processes of both sub-machines controlled, ie this processing machine has only a single program control despite its double machine character. The submachine 24 also has a workpiece coordinate guide 44 which corresponds to that 31 of the submachine 23. Accordingly, the workpiece 18 in this processing machine 1 can be held simultaneously on its left edge area 32 and on its right edge area 33. The workpiece holding device for the left edge area 32 essentially consists of the holding members 14 and 15 with their clamping claws 16 and 17 and is designated by 34. Accordingly, an additional workpiece holding device 35 is provided on the submachine 24 and is only shown schematically there. As already explained, the holding devices 34 and 35 can be moved independently and in the same direction in order to move the workpiece 18 longitudinally and transversely or obliquely in a certain manner, and they can also be actuated individually, that is to be clamped or released. This is preferably done with the help of the machine control, in particular a program control of the machine.

In a manner not shown, the two workpiece holding devices 34 and 35 can be mechanically coupled to one another. In this case, it is sufficient if, for example, only the workpiece holding device 34 is controlled. The other is then taken along in the same direction via the mechanical connection. The attachment and, if necessary, mutual displacement - in the case of two holding members 14, 15 - is expediently not mechanically coupled for the two sub-machines, but is carried out separately for each sub-machine.

In the embodiment of FIG. 1, the two arms 26 and 27 of this processing machine point towards one another with their free ends. In contrast, the boom 27 of the processing machine according to FIG. 2 has a boom extension 36. While in FIG. 1 the processing stations 37 and 38 are each assigned to the area of the free end of the boom, the processing stations 39 and 40 are located in the area in the other variant the free end of the boom 27 on the one hand and the boom extension 36 on the other. In the variant according to FIG. 2, the workpiece holding device 34 is also arranged in mirror image to the additional workpiece holding device 35 of the arm 27 and for this reason an auxiliary arm 41 is attached to the arm extension 36. Otherwise, an upper tool part, in particular a punch 42 or 43, is also shown schematically there. However, the two processing machines of each variant do not necessarily have to be of the same design, as has already been explained above. In particular, the auxiliary arm 41 can have an additional support 45 (as shown in broken lines).

Claims (9)

1. Processing machine for flat workpieces with a processing station and a first workpiece holding device (34) which can be moved and operated in a straight line (e.g. in the X direction) in relation to its working tool by means of a first feeding device (11, 12, 13) and with an additional workpiece holding device (35) which at least as an alternative to the first one can be moved and operated in the same direction by means of an additional feeding device (7, 4, 8), characterised in that the two workpiece holding and feeding devices which can be assigned to the two opposite workpiece edges can be moved and for preference also operated by means of a common control device (30) both individually as also jointly within a common X-Y plane as well as being associated with workpiece coordinate guides with the same or parallel X and Y axes.

2. Machine according to claim 1, characterised in that the common control (30) can be programmed.

3. Machine according to claim 1 or 2, characterised in that the two workpiece holding devices (34,35) are arranged opposite each other with a clearance, whereby clamping shoes (16,17) of the first workpiece holding device (34) point in approximately the opposite direction to clamping shoes of the additional workpiece holding device (35).

4. Machine according to claim 3, characterised in that the lateral clearance of the holding components (14, 15) of each holding device (34 or 35) can be adjusted separately.

5. Machine according to at least one of the previous claims, characterised in that the two workpiece holding devices (34, 35) are connected to each other mechanically.

6. Machine according to at least one of the previous claims, characterised by two processing stations (37, 38, 39, 40) for the workpiece (18) which are remote from each other.

7. Machine according to at least one of claims 3 to 6, characterised in that the two processing stations (37, 38, 39, 40) are positioned apart from each other with a fixed clearance in the same direction, as the two workpiece holding devices (34, 35)

8. Machine according to claim 7, characterised in that the two processing stations (37, 38) are located at least in part on machine arms (26, 27) facing each other.

9. Machine according to claim 7, characterised in that the second processing station (40) is located at least in part on an extension (36) of a machine arm (27).

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